The invention relates to a process for the preparation of Roflumilast by reaction of an activated form of 3-(cyclopropylmethoxy)-4-(difluoromethoxy)-benzoic acid with an activating agent selected from (a) carbonyldiimidazole (CDI), (b) 1,1&prime；-carbonyl-di-(1,2,4-triazol) (CDT), (c) 1,1&prime；-carbonyl-bis-(2-methylimidazol), (d), 1&prime；-carbonyl-dipyperidin, (e) N,N&prime；-dicyclohexylcarbodiimide (DCC), (f) N,N&prime；-diisopropylcarbodiimide (DIC), (g) 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and a combination of one of the previous (a)-(g) with (h) N-hydroxysuccinimide or (i) N-hydroxyphthalimide, and the subsequent reaction with 3,5-dichloropyridine-4-amine in the presence of an inorganic base. The invention also relates to the synthesis intermediates.
